1) Field of the Invention
The present invention relates to an amino compound obtained by addition reaction of an alkenyl compound to a diamine represented by the following formula (1) and a process for producing the same. This amino compound is applicable to a curing agent and a raw material thereof for an epoxy resin to be utilized in a very wide field including application to coating such as an electrodeposition coating for motor car, a heavy-duty paint for ship, bridge and land and marine iron structure, and inner coat of drinking can, application to electricity and electronics to be used in household electric products, communication equipments and control systems of motor car and airplane such as a laminated plate, an electric semiconductor sealing compound, an insulating powder coating, and coil impregnation, application to civil engineering and construction such as earthquake-proof of bridge, lining, reinforcement and repair of concrete structure, a flooring material of building, lining of water supplying facility and sewerage, and pavement for waste water and permeating water, application to adhesive for vehicle and airplane, and application to composite material for airplane, industrial materials and sports equipment, and to a chain extender and a raw material thereof of a polyurethane resin to be utilized in a very wide field including cloths, sports equipment, home appliances, electronics, medical apparatuses, motor cars, transporting apparatus, civil engineering and construction and industrial materials as foam, elastomer, coating, adhesive, binder, fiber, leather, flooring material, water proof material, athletic material, sealant, coking, medical material and fiber treating agent.
H2Nxe2x80x94H2Cxe2x80x94Axe2x80x94CH2xe2x80x94NH2xe2x80x83xe2x80x83(1)
wherein A is a phenylene group or a cyclohexylene group.
2) Prior Art
It has widely known that various polyamino compounds are used as a curing agent for epoxy resin and a raw material thereof or a chain extender and a raw material thereof of a polyurethane resin. Particularly, a curing agent for epoxy resin containing the diamine represented by the formula (1) and a curing agent for epoxy resin used the above-mentioned diamine as a raw material have a feature that curing of an epoxy resin composition fast proceeds since their reactivity with an epoxy resin is higher than a curing agent for epoxy resin containing other aromatic polyamino compound or an aliphatic polyamino compound and a curing agent for epoxy resin used the same as a raw material. Further they have features to provide a coated film excellent in both gloss and levelling and a cured product excellent in both water resistance and chemical resistance.
However, on the other hand, a curing agent for epoxy resin containing the diamine represented by the formula (1) and a curing agent for epoxy resin used the above-mentioned diamine as a raw material have defects that an epoxy resin composition used said curing agent for epoxy resin exhibits a short pot life and its workability is inferior since their reactivity with an epoxy resin is high.
Hitherto, it has been known that when a cyanoethylated polyamino compound obtainable by Michael addition reaction of a polyamino compound and an acrylonitrile is used as a curing agent for epoxy resin, long pot life is provided to an epoxy resin composition, e.g., xe2x80x9cNew Epoxy Resinxe2x80x9d edited by Hiroshi Kakiuchi, published by Shokodo in Japan, 1985, P186. However, acrylonitrile has been designated as a specific chemical substance and a deleterious substance in Japan and exhibits high harmfulness. Thus, recently, restriction on its handling has been increased from the aspects of safety and hygiene.
Further, Japanese Patent Kokai (Laid-open) No. 8-269196 relates to a process for producing a star form-or a comb form-branched aliphatic polyamino compound and a curing resin composition and discloses an aliphatic polyamino compound able to control optionally a pot life after mixing other resin and a curing resin used the same as one component. However, an aliphatic polyamino compound with a low viscosity at a room temperature exhibits a small prolongation effect of a pot life.
Japanese Patent Kokai (Laid-open) No. 11-80322 relates to a compound obtainable by Michael addition reaction of a polyamino compound and an unsaturated carboxylic acid ester compound and discloses a method for prolongation of pot life in curing at a room temperature of an epoxy resin composition with a low viscosity at a room temperature and low harmfulness. However, when it is used as a curing agent for epoxy resin, the pot life of an epoxy resin composition used the curing agent becomes short since, during its long time preservation, ester-amide exchange reaction of an ester group and an amino group present in the amino compound proceeds, so that viscosity is increased due to production of amide and the ester group is decreased.
It has been already known that addition reaction of various amino compounds and an alkenyl compound produces the corresponding amino compound. When an alkenyl compound has a strong electron withdrawing group such as a cyano group or carboxylic acid ester, its reaction readily proceeds. On the other hand, when it has no strong electron withdrawing group, the reaction with the amino compound becomes difficult, but it becomes possible by use of a catalyst (xe2x80x9cProgress of Complex Catalyst Chemistryxe2x80x9d written by Shunichi Murahashi, Kagakuzokan 109, P167-176, 1986, published by Kagaku Dojin, in Japan). For example, acrylonitrile with a cyano group reacts readily with various amino compounds and a cyanoethylated amino compound thus obtained has been applied widely in the field of a curing agent for epoxy resin (xe2x80x9cNew Epoxy Resinxe2x80x9d edited by Hiroshi Kakiuchi, published by Shokodo in Japan, P186, 1985). Further, reaction of acrylate or methacrylate having carboxylic acid ester with various amino compounds produces the corresponding amino compound (E.H. RIDDLE: MONOMERIC ACRYLIC ESTERS, P153-155, 1954)
Even in case of divinyl benzene where an alkenyl compound has no strong electron withdrawing group, it reacts N,Nxe2x80x2-diethyl ethylenediamine by use of an alkaline metal catalyst whereby the corresponding amino compound is obtained (Japanese Patent Kokai (Laid-open) No. 55-11523). It has been known that a nitrogen-containing monomer with carbon-carbon double bond and amine is obtained by the reaction disclosed in Japanese Patent Kokai (Laid-open) No. 55-11523.
An object of the present invention is to provide an amino compound in which a long pot life is provided to an epoxy resin composition used the amino compound as a curing agent for epoxy resin and a process for producing the same.
As a result of extensive studies to provide above-mentioned novel amino compound in order to solve the above-mentioned prior art problems, the inventors have found that a novel amino compound is obtained by addition reaction of the diamine represented by the formula (1) and an alkenyl compound without necessitating use of a harmful raw material such as acrylonitrile designated as a specific chemical substance and a deleterious substance in Japan and the amino compound thus obtained causes no change of both viscosity during preservation and a pot life of an epoxy resin composition used the amino compound as a curing agent for epoxy resin and a long pot life is provided to an epoxy resin composition used the amino compound as a curing agent for epoxy resin, and have accomplished the present invention.
That is, the present invention provides an amino compound obtained by addition reaction of diamine represented by the following formula (1) and an alkenyl compound.
H2Nxe2x80x94H2Cxe2x80x94Axe2x80x94CH2xe2x80x94NH2xe2x80x83xe2x80x83(1)
wherein A is a phenylene group or a cyclohexylene group.
The present invention provides also a process for producing an amino compound which comprises performing addition reaction of diamine represented by the formula (1) and an alkenyl compound in the presence of a strong base catalyst.
Further, the present invention provides a curing agent for epoxy resin containing the above-mentioned amino compound, an epoxy resin composition comprising an epoxy resin and the above-mentioned amino compound as a curing agent for epoxy resin and a cured product cured the epoxy resin composition.